文章基本信息

标题：Flotation and retreat of a lake-calving terminus, Mendenhall Glacier, southeast Alaska, USA
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作者：Eleanor S. Boyce ; Roman J. Motyka ; Martin Truffer 等
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2007
卷号：53
期号：181
页码：211-224
DOI：10.3189/172756507782202928
出版社：Cambridge University Press
摘要：Mendenhall Glacier is a lake-calving glacier in southeastern Alaska, USA, that is experiencing substantial thinning and increasingly rapid recession. Long-term mass wastage linked to climatic trends is responsible for thinning of the lower glacier and leaving the terminus vulnerable to buoyancy-driven calving and accelerated retreat. Bedrock topography has played a major role in stabilizing the terminus between periods of rapid calving and retreat. Lake-terminating glaciers form a population distinct from both tidewater glaciers and polar ice tongues, with some similarities to both groups. Lacustrine termini experience fewer perturbations (e.g. tidal flexure, high subaqueous melt rates) and are therefore inherently more stable than tidewater termini. At Mendenhall, rapid thinning and simultaneous retreat into a deeper basin led to flotation conditions along approximately 50% of the calving front. This unstable terminus geometry lasted for approximately 2 years and culminated in large-scale calving and terminus collapse during summer 2004. Buoyancy-driven calving events and terminus break-up can result from small, rapidly applied perturbations in lake level.